Results 81 to 90 of about 2,536 (230)

Deep learning-enabled size estimation of comets indicates a more dynamic early solar system

Nature Communications
The formation and evolution of the Solar System’s two major comet reservoirs, the Oort Cloud and the Scattered Disk, remain poorly constrained. Observations of comet flux imply a population ratio between these reservoirs that exceeds predictions from ...
Shunjing Zhao, Xian Shi, Hanlun Lei, Man-To Hui, Jianchun Shi   +4 more
doaj   +1 more source

The correspondence of Giovanni Santini and Giuseppe Lorenzoni, directors of the Astronomical Observatory of Padua in the 19th century

Annals of Geophysics, 2009
<p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 9.0px Times;">Giovanni Santini was appointed director of the Astronomical Observatory of Padova from 1817 to 1877. His scientific correspondence covers a period from 1807 to 1874. Most of the letters
Luisa Pigatto
doaj   +1 more source

The Great Cosmic Silence: What Does the Fermi Paradox Tell About the Future of Humanity?

Global Policy, EarlyView.
ABSTRACT This article examines how institutional time horizons shape the long‐term survival prospects of human technological civilisation. While research on global catastrophic and existential risks has expanded, the temporal structures of political‐economic institutions remain underexamined.
Heikki Patomäki
wiley   +1 more source

A Potential Signature of HD 7977’s Passage among Observed Long-period Comet Orbits

The Planetary Science Journal
It is generally presumed that the tidal field of the Milky Way’s disk is the main perturbation that has driven observed long-period comets (LPCs) from the Oort cloud into the inner solar system.
Nathan A. Kaib, Sean N. Raymond
doaj   +1 more source

Cometary Dynamics—Formation and Evolution of the Oort Cloud

Astronomy
In this review, the formation of the Oort Cloud is illuminated from several aspects. One is the history of the subject with an outline of the fundamental discoveries by Öpik, Oort and Hills. It is argued that the basic reason for judging Oort as the real
Hans Rickman
doaj   +1 more source

On the Rate of Ejection of Dust by Long-Period Comets [PDF]

Symposium - International Astronomical Union, 1972
A model of the interplanetary dust medium that includes two subsystems, a spherical component and a flat one, has been proposed by the author as a result of analysis of radar meteor orbits. The disintegration of short-period comets is the main source of the flat dust cloud, while the disintegration of long-period comets is the main source of the ...
openaire   +1 more source

Psychedelic‐assisted treatment for substance use disorder: A narrative systematic review

Addiction, EarlyView.
Abstract Background and aims This is the first systematic review of the extant literature on all major psychedelic‐assisted treatment for alcohol use disorder (AUD), tobacco use disorder (TUD) and other substance use disorders (SUD). We aimed to summarise the evidence for efficacy of psychedelic‐assisted treatment for AUD, TUD, and SUD; to evaluate its
Theodore Piper, Francesca Small, Sam Brown, Michael Kelleher, Luke Mitcheson, James Rucker, Allan H. Young, John Marsden   +7 more
wiley   +1 more source

Long Propagation Periods of Residuals in the Motion of a Comet [PDF]

Symposium - International Astronomical Union, 1979
P/Halley In a previous paper (Kiang 1973), I derived a differential equation which governs the behaviour of the residual O - C in the time of perihelion passage of a comet. The work was stimulated by the discovery (Brady 1972) that a long periodicity of about 600 years seemed to be present in the residual for P/Halley.
openaire   +1 more source

Developing a core outcome set for generalized anxiety disorder during the perinatal period: Identifying core treatment outcomes in perinatal anxiety

British Journal of Clinical Psychology, EarlyView.
Abstract Background Generalized anxiety disorder during the perinatal period (pGAD) is highly prevalent and associated with adverse outcomes for both mother/birthing person (BP) and child. Yet, most treatment studies rely on researcher‐selected outcomes that may not reflect patient priorities.
Emma M. Stallwood, Annaba Tasnia, Daniela Giansante, Briar E. Inness, Benicio N. Frey, Randi E. McCabe, Sheryl M. Green   +6 more
wiley   +1 more source

The Effect of Dwarf’s Planets Pluto and Eris upon Long Period Comets

Journal of Kufa-Physics, 2017
The orbit of long period comets overlapped with that of dwarf’s planet Pluto and Eris. The gravitational effects arise from dwarf’s planets as well as the eight planets   have been involved in orbits calculations.
Hayder Hasan Jawad
doaj